According to Leon Brenner in The Autistic Subject, autistic people are unable to cipher their jouissance via signifiers, instead they delimit their jouissance using signs. Now let’s ask a question: Has the autistic climate activist Greta Thunberg been unable to cipher her jouissance using signifiers? 
It would be quite unjust to say that Greta Thunberg has been inarticulate or have failed to communicate her message. On the contrary, she articulated her message quite effectively using the signifiers in language and she was also heard well by immensely large crowds. She gave impressive speeches on crucial global summits to world leaders and it’s estimated that millions of people participated in the Global Climate Strikes organized by her Fridays For Future.
On the other hand, it would be just to say that Greta Thunberg absolutely sticks to signs and fundamentally refuses something about the order of signifiers: She refuses the dominant symbolic hegemony of signifiers like ‘profit’ and ‘growth’ by absolutely sticking to a definite set of scientific signs about the changing climate. So what is she resisting against, precisely?
Neurotics are known to have perverse traits, one of which is to disavow fatal ominous signs as in climate denialism. In order to disavow the reality of these ominous signs, the neurotics ‘neuroticize’ these signs by turning them into signifiers that represent imaginary subjects for other signifiers. The invention of such imaginary subjects is the essence of the propaganda that propagates the symbolic order. One such imaginary subject is the Mother Earth who supposedly took vengeance upon the mischievous humanity by sending them the novel coronavirus and thereby condemning them to lockdowns. What the autistic subject resists is precisely this neuroticizing propaganda.
Recall the paradigmatic ominous sign that the pervert disavows: The mother does not have a penis. The crucial fact is that the presence of the vagina is a neutral sign that does not represent any subject, whereas it gets neuroticized when it’s turned into a signifier of lack in the (m)Other . The autistic subject sticks to the neutrality of the sign and resists its ’emotional’ neuroticization and that’s why (s)he is viewed as “necessarily split between his emotions and his intellect” (Maleval quoted in Brenner).
Freud called neurosis the negative of perversion. Since the autistic subject resists the disavowal of the sign, perhaps we should call perversion (and the perverse traits in neurotics) the negative of autism. Greta Thunberg absolutely resisted the disavowal of the scientific signs about the climate crisis but the irony of history is that the neurotic masses elevated her to the subject that is represented by the signifier ‘climate’ and thus turned her into the very means of that disavowal.
 I must point out that I don’t represent any clinical knowledge.
 Why don’t we call S(Ⱥ) the sign of the lack in the Other, insofar as it does not represent the subject for other signifiers?